LIMNOLOGY: HISTORY, FIELD OF STUDY, BRANCHES, RESEARCH - BIOLOGY - 2025

The Limnology is the science that studies the inland bodies of water as interrelated ecosystems with terrestrial ecosystems and the atmosphere. Describe and analyze the physical, chemical and biological factors of inland waters to explain their composition, structure, energy, and living organisms.

The term "limnology" comes from the words limne (divinity associated with water) and logos (treatise or study). It was first employed by François Alphonse Forel, a Swiss scientist considered the father of this discipline for his great contributions during the 19th century.

Limnology, the study of inland waters. Source: www.flickr.com

Limnology has evolved remarkably throughout its history; initially it only included the study of lakes, which were considered as superorganisms, without interconnection with the environment. At present, the study of continental waters considers interactions with the environment and their importance in the cycles of matter and energy.

History

Ancient limnology

The first contributions to the knowledge of the lakes appear in ancient Europe, with isolated observations, without interconnections between them.

Between 1632 and 1723, A. van Leewenhoek made the first descriptions of aquatic microorganisms, thanks to the appearance of the microscope, which meant an important advance in the knowledge of aquatic life.

In 1786 the first classification of aquatic microscopic organisms was published, carried out by the Danish biologist Otto Friedrich Müller, called Animacula Infusoria Fluviatilia et Marina.

With the appearance of the first biological stations, knowledge in limnobiology reached its fullness. In 1888 the first experimental station was founded in the Bohemian forests of the Czech Republic. Subsequently, the number of biological stations in Europe and the United States multiplied rapidly.

Scientists of the time made great contributions to the knowledge of life in freshwater bodies. Studies in taxonomy, feeding mechanisms, distribution, migrations, among others, stand out.

Modern limnology

Modern limnology emerged at the end of the 19th century, with the discovery of the freshwater planktonic community by PE Müller in 1870.

In 1882 Ruttner establishes that limnology includes ecological interactions, beyond the descriptive study of the biotic associations that occur in the body of water.

In 1887, SA Forbes published an essay called The Lake as a Microcosm, in which he analyzed the lake as a system in dynamic equilibrium of matter and energy with living organisms.

In 1892, FA Forel published the results of his research in Lake Leman (Switzerland), focused on the geology, physicochemical characterization and description of living organisms in the lake.

In 1917 Cole includes a second objective to limnology; the study of the cycles of matter, with special emphasis on biogeochemical cycles.

In 1935 Welch defined limnology as the study of the biological productivity of inland waters. This definition includes for the first time in limnology the focus on productivity and the study of lotic systems (rivers and streams), as well as lentic systems (lakes).

In 1975 Hutchinson and Golterman characterize limnology as an interdisciplinary science that depends on geology, meteorology, physics, chemistry and biology.

In 1986 Lehman described two fields of study linked to limnology. A first field focused on the physicochemical (thermodynamic) properties of bodies of water. A second field that studies biological processes at the population and community level, controlled by natural selection.

During the 1990s, faced with the growing demand for water and the global threat of its reduction in quantity and quality, an applied vision of limnology emerged that focuses on environmental management.

Contemporary limnology

The limnology of the XXI century maintains the vision of the importance of the knowledge of the lentic and lotic systems to favor an environmental management of water that allows humanity to enjoy the water resource and its social, economic and natural benefits.

Field of study

Limnology is considered a branch of ecology that focuses on inland aquatic ecosystems, including lakes, ponds, groundwater, ponds, streams, and rivers.

It studies both the flow of matter and energy, as well as the composition, structure and dynamics of living organisms present in continental waters at the level of individuals, species, populations and communities.

Understanding all the processes and mechanisms that make up biodiversity and the physicochemical responses of continental aquatic environments requires the integration of multiple scientific disciplines, such as chemistry, physics, biology, climatology, hydrology, geology, among others.

Limnology also integrates the processes of continental waters with terrestrial ecosystems. It considers the effects of water drainage and the contribution of matter and energy from the basins. Likewise, it takes into account the exchanges that occur between bodies of water and the atmosphere.

The study of inland waters also involves the identification of environmental threats and the description of their effects on the ecosystem. Likewise, it implies the search for solutions, such as the mitigation of climate change, the control of exotic species and the restoration of ecosystems.

Branches

The branches of limnology arise according to the type of continental water body under study.

Stagnant water limnology

This branch of limnology studies lentic ecosystems, better known as lakes. Both natural surface waters and artificial reservoirs, ponds or dams are included.

Tanganyika lake, Zambia. Source: Worldtraveller, via Wikimedia Commons

Limnology of running waters

Running water limnology studies lotic ecosystems, such as rivers or streams, characterized by a predominantly horizontal and unidirectional flow of water.

Amazon River. Source: Peter Angritt, from Wikimedia Commons

Groundwater limnology

This branch studies the processes that occur in underground water reservoirs. Research on the biogeochemical processes that shape the chemical characteristics of groundwater are included.

Groundwater measurement. Source: www.pixabay.com

Limnology of saline lakes

This branch studies saline lakes, which constitute 45% of the world's inland lakes. His research focuses on the particular characteristics of these ecosystems, including their chemical, physical and biological descriptions.

Great Salt Lake, United States. Source: User Draxfelton on en.wikipedia, from Wikimedia Commons.

Recent research

Investigations in tropical lakes

Most research in lentic environments has been carried out in lakes in the temperate northern regions. However, the biogeochemical dynamics of large tropical lakes are different from those recorded for temperate lakes.

Li and colleagues published an article in 2018 on the geochemistry of sediments and the contribution to the carbon and nutrient cycling in a tropical lake located in Malawi (East Africa).

The results indicate a significant contribution of sediments on the biogeochemical budgets of the lake. Furthermore, they show that sedimentation rates have increased significantly in the last ten years.

Investigations in artificial reservoirs or dams

The number of artificial ponds and dams have increased rapidly in recent years.

Even though a good understanding of natural lakes can help to understand artificial ecosystems, they can present multiple characteristics that differentiate them from natural ecosystems. Because of this, research in artificial environments is of great importance today.

Znachor et al. (2018) analyzed data from 36 environmental variables taken over 32 years in a small reservoir in the Czech Republic. The objective of the research was to detect trends in climatic and biogeochemical characteristics.

Almost all the environmental variables showed variable trends over time. Trend reversals were also identified. For example, dissolved organic carbon showed a tendency to grow linearly continuously.

This study also showed a change in trends in the late 1980s and during the 1990s. The authors interpret this change as a response to some socioeconomic changes that occurred in the region.

Another important result of this study is a change in the hydraulic conditions of the dam that occurred in 1999. This occurred after the increase in the retention volume of the dam, as a result of an administrative decision taken after a period of heavy rainfall.

This example shows how research in limnology can show us the effects of socioeconomic factors and political decisions on the functioning of artificial ecosystems. In turn, these can help us understand the effects on natural ecosystems.

Research on paleolimnology

Paleolimnology is the study of sediments deposited in lakes with the aim of reconstructing the natural history or the change in environmental variables of a lake or its environment in times past. For this, different methodologies are used, such as the analysis of diatom microfossils, pollen or ostracods.

Novaes Nascimento and collaborators published an article in 2018 on a paleobiological investigation in the Peruvian Andes that reconstructs the history of Lake Miski, a small saltwater refuge located at 3,750 meters above sea level.

The results of the carbonate stratigraphy and the fossil diatom community showed a decrease in the level of the lake during the middle Holocene, however, it never completely dried up.

History shows that Lake Miski has been part of the landscape for 12,700 years, even as many shallow Andean lakes have dried up.

References

1. Banderas, AG and González, R. (1996). Limnology, a revision of the concept. Hydraulic Engineering in Mexico, XI (1): 77-84.
2. Basavarajappa, SH, Raju, NS and Hosmani, SP (2014) Limnology: A Critical Review. Current World Environment, 9 (3), 741-759.
3. Li, J., Brown, ET, Crowe, SA and Katsev, S. (2018). Sediment geochemistry and contributions to carbon and nutrient cycling in a deep meromictic tropical lake: Lake Malawi (East Africa). Journal of Great Lakes Research 44 (6): 1221-1234
4. Novaes Nascimento, M., Laurenzi, AG, Valencia, BG, Van, R. and Bush, M. (2018). A 12,700-year history of paleolimnological change from an Andean microrefugium. The Holocene.
5. Welsh, PS (1952). Limnology. McGraw Hill. London 538.
6. Znachor, P, Nedoma, J, Hejzlar J, Seďa J, Kopáček J, Boukal D and Mrkvička T. (2018). Multiple long-term trends and trend reversals dominate environmental conditions in a man-made freshwater reservoir. Science of the Total Environment 624: 24-33.